Report: frequency of severe storms in Midwest doubled over past 50 years

Average frequency of days with 3 inches or more of precipitation per weather station per year. Dots indicate annual average frequency per station, the blue line the 1961-2011 linear trend line, and the dashed line the average frequency 1961-1990.

The report analyzed precipitation data from more than 200 weather stations in eight Midwestern states.

It found that for the period from 1961 to 2011, the frequency of days with more than 3 inches of rain increased by upwards of 80 percent in both Illinois and Missouri, and by more than 100 percent across the Midwest as a whole.

And Rocky Mountain Climate Organization president and lead author on the report, Stephen Saunders, says all that heavy rainfall has contributed to an increase in damaging floods.

“Our study showed that the year with the most extreme storms in the Midwest was 2008. The second highest year was 1993,” Saunders said. “And as people who lived through those floods in the Midwest know, those were two years with the worst flooding the Midwest has had in more than 80 years.”

Severe floods in the Midwest in 1993 and 2008 caused tens of billions of dollars in damages.

And Saunders says global models predict climate change will increase the frequency of major rain storms.

“This increase in extreme storms represents what looks to me to be the Midwest’s greatest vulnerability to the effects of human-caused climate change.”

The report urges local, state, and federal officials to do more to address climate change and flooding. That includes setting standards to curb greenhouse gas emissions from vehicles, power plants, and large industrial sources, and increasing the use of green infrastructure in urban areas to absorb rainfall and runoff.